Catalyst layer for fuel cell

Patent metadata

Field	Value
Publication number	US-11508971-B2
Application number	US-202017072306-A
Country	US
Kind code	B2
Filing date	Oct 16, 2020
Priority date	Dec 2, 2019
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

There is provided a catalyst layer for a fuel cell that can inhibit reduction in water electrolysis function. The catalyst layer for a fuel cell according to this disclosure comprises carbon supports on which Pt particles are supported, and Ir oxide particles, wherein the ratio of the mean primary particle size of the Ir oxide particles with respect to the mean primary particle size of the Pt particles is 20 or greater. The mean primary particle size of the Pt particles may be 20.0 nm or smaller and the mean primary particle size of the Ir oxide particles may be 100.0 nm to 500.0 nm.

First claim

The invention claimed is:

1. A catalyst layer for a fuel cell, comprising;
Pt particles on carbon supports, and
Ir oxide particles,
wherein the ratio of the mean primary crystallite diameter of the Ir oxide particles with respect to the mean primary crystallite diameter of the Pt particles is 20.0 or greater.

2. The catalyst layer for a fuel cell according to claim 1 , wherein:
the mean primary crystallite diameter of the Pt particles is 10.0 nm or smaller, and
the mean primary crystallite diameter of the Ir oxide particles is 100.0 nm to 500.0 nm.

3. The catalyst layer for a fuel cell according to claim 1 , wherein the ratio of the mass of the Pt particles with respect to the carbon supports is 0.18 to 0.35.

4. The catalyst layer for a fuel cell according to claim 1 , wherein the mean primary particle size of the carbon supports is 50.0 nm to 300.0 nm.

5. The catalyst layer for a fuel cell according to claim 1 , wherein the area-to-weight ratio of the carbon supports is 100 m 2 /g or lower.

6. The catalyst layer for a fuel cell according to claim 1 , which further comprises an ionomer, and wherein:
the ratio of the mass of the ionomer with respect to the mass of the carbon supports is 1.2 to 1.6.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kitao Noriyuki

Classifications

• H01M4/92

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title

• C25B11/091

  consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds · CPC title

• H01M4/8673

  Electrically conductive fillers · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• H01M4/926 Primary

  on carbon or graphite · CPC title